scholarly journals Characterization of siderophore producing arsenic-resistantStaphylococcus sp. strain TA6 isolated from contaminated groundwater of Jorhat, Assam and its possible role in arsenic geocycle

2017 ◽  
Author(s):  
Saurav Das ◽  
Madhumita Barooah

AbstractThe presence of arsenic in sediments, carbonaceous rocks are geogenic, while its entry into the aquifers is mediated by several factors including microorganisms. It is well known that the microorganisms play a crucial role in the biogeochemical cycle of different elements. However, the precise role of bacteria in regulating the concentration of arsenic in Brahmaputra valley has not been investigated in detail. In this paper, we report the isolation of arsenic resistant bacterium TA6 with active arsenate reduction efficiency. The isolate was able to grow in arsenate concentration (250 mM) and arsenite (30 mM). Along with resistance to inorganic arsenic, it showed cross-tolerance to other heavy metals like Hg+2, Cd+2, Co+2, Ni+2, Cr+2. The bacterium also had a high siderophore activity (78.7 ± 0.004 μmol), which is positively correlated with the resistance aptitude. The biochemical test showed the TA6, a gram-positive bacterium which can hydrolyze starch and casein, produce catalase enzyme and utilizes citrate as a metabolic trait. Molecular and chemotaxonomic identification of TA6 based on 16S rRNA and FMAE analysis showed similarity with members ofStaphylococcusgenus with significant difference in sequence similarity and fatty acid composition. Based on 16S rRNA and FAME analysis it was identified asStaphylococcus sp.TA6. Rate of biotransformation showed bacterium could reduce ~88.2% of initial 2mM As(V) into As(III). The characterization of arsenate reductase enzyme with NADPH coupled assay showed the highest activity at pH 5.5 and temperature 50°C.

2020 ◽  
Vol 222 ◽  
pp. 02050
Author(s):  
Marat Lutfulin ◽  
Darya Zaripova ◽  
Oksana Moiseeva ◽  
Semen Vologin ◽  
Ayslu Mardanova

Identification of patterns of formation of bacterial communities of the rhizosphere and rhizoplane of potato (Solanum tuberosum L.), the most important agricultural crop, is necessary for the introduction and maintenance of sustainable organic farming. The purpose of this work was the study of the biodiversity of the bacterial microbiota of the rhizosphere and rhizoplane of Early Zhukovsky potato, cultivated on gray forest soils. Comparative analysis based on sequencing of the 16S R RNA gene showed a significant difference in the representation of different groups of bacteria in these potato root compartments. Thus, the proportions of the dominant bacteria in the rhizosphere and rhizoplane of the Proteobacteria phylum reach 47.66% ± 7.22 % and 86.35 % ± 0.53%, respectively (P < 0.05). In contrast, the representation of phylum Bacteroidetes and Firmicutes in the rhizosphere is significantly higher and reaches 41.45 % ± 10.42% and 6.49 % ± 3.23%, respectively, compared to the rhizoplane (7.84 % ± 1.24 % and 0.43 % ± 0.48 %, (P < 0.05). At the same time, Actinobacteria phylum bacteria are present in both compartments in approximately equal amounts (4.40 % ± 1.81% in the rhizosphere and 5.37 % ± 1.42% in the rhizoplane). Thus, it was found that potato forms different bacterial communities in the rhizosphere and rhizoplane in quantitative proportions, which is probably determined by the functional role of these microorganisms in the plant physiology.


2004 ◽  
Vol 54 (6) ◽  
pp. 1991-1995 ◽  
Author(s):  
Nomeda Kuisiene ◽  
Juozas Raugalas ◽  
Donaldas Chitavichius

Obligately thermophilic, aerobic, proteolytic, endospore-forming strain N-3T was isolated from a high-temperature oilfield in Lithuania. 16S rRNA gene sequence analysis placed this strain in genetic group 5 of the endospore formers. Geobacillus thermoleovorans appeared to be the closest phylogenetic neighbour (99·4 % sequence similarity). The G+C content of strain N-3T was 52·5 mol% and matched the range established for the genus Geobacillus. Studies of DNA–DNA relatedness and morphological and physiological analyses enabled strain N-3T to be described as a member of the genus Geobacillus, but could not assign this strain to any other known species of this genus. Results of this polyphasic study allowed characterization of strain N-3T as a novel species in the genus Geobacillus – Geobacillus lituanicus sp. nov. This species can be distinguished from G. thermoleovorans and Geobacillus stearothermophilus on the basis of 16S rRNA gene PCR-RFLP assays with the restriction endonucleases AluI, HaeIII and TaqI. The type strain of the novel species is N-3T (=DSM 15325T=VKM B-2294T).


2019 ◽  
Author(s):  
Creciana Maria Endres ◽  
Ícaro Maia Santos de Castro ◽  
Laura Delpino Trevisol ◽  
Michele Bertoni Mann ◽  
Ana Paula Muterle Varela ◽  
...  

AbstractThe production of sheep’s milk cheese has grown in recent years since it is a high value-added product with excellent properties. As such, it is necessary to provide data on the microbiota and organoleptic characteristics of this product, as well as the influence of these microorganisms on public health. Thus, the aim of the present study was to characterize the microbial community of different types of sheep cheeses using high-throughput sequencing of the 16S rRNA gene. The study was conducted with four groups of cheese: colonial, fresh, feta, and pecorino (n = 5 samples per group). The high-throughput 16S rRNA amplicon sequencing revealed 55 operational taxonomic units in the 20 samples, representing 9 genera of the two bacterial phyla Firmicutes and Proteobacteria. The predominant genera in the samples were Streptococcus and Lactobacillus. When evaluating alpha diversity by the indexes of Simpson, Chao1, Shannon, and Skew no significant differences were observed between the groups. Evaluating of the beta diversity using Bray-Curtis dissimilarity, the group of colonial cheeses presented a significant difference when compared to the feta (q = 0.030) and pecorino groups (q = 0.030). Additionally, the fresh group differed from the pecorino group (q = 0.030). The unweighted Unifrac distance suggests that the colonial cheese group differed from the others. Moreover, the feta cheese group differed from the fresh group. The distance-weighted Unifrac suggests that no significance exists between the groups. According to this information, the microbiota characterization of these cheese groups was useful in demonstrating the bacterial communities belonging to each group, its effects on processing, elaboration, maturation, and public health.


2015 ◽  
Vol 65 (Pt_12) ◽  
pp. 4724-4729 ◽  
Author(s):  
Fazel Pourahmad ◽  
Mateja Pate ◽  
Matjaž Ocepek ◽  
Emanuele Borroni ◽  
Andrea M. Cabibbe ◽  
...  

The name ‘Mycobacterium angelicum’ dates back to 2003 when it was suggested for a slowly growing mycobacterium isolated from freshwater angelfish. This name is revived here and the novel species is proposed on the basis of the polyphasic characterization of four strains including the original one. The four strains presented 100 % 16S rRNA gene sequence similarity with Mycobacterium szulgai but clearly differed from M. szulgai for the milky white aspect of the colonies. The sequence similarity with the type strain of M. szulgai ranged, in eight additionally investigated genetic targets, from 78.9 to 94.3 %, an evident contrast with the close relatedness that emerged at the level of 16S rRNA gene. The average nucleotide identity between the genomes of M. szulgai DSM 44166T and strain 126/5/03T (type strain of the novel species) was 92.92 %, and supported the status of independent species. The confirmation of the name Mycobacterium angelicum sp. nov. is proposed, with strain 126/5/03T ( = CIP 109313T = DSM 45057T) as the type strain.


2021 ◽  
Author(s):  
Surendra Raj Sharma ◽  
Gary Crispell ◽  
Ahmed Mohamed ◽  
Cameron Cox ◽  
Joshua Lange ◽  
...  

AbstractAlpha-Gal Syndrome (AGS) is an IgE-mediated delayed-type hypersensitivity reaction to the oligosaccharide galactose-⍰-1,3-galactose (α-gal) injected into humans from the lone star tick (Amblyomma americanum) bite. This study aims at the functional characterization of two tick enzymes, α-D-galactosidase (ADGal) and α-1,4 galactosyltransferase (β-1,4GalT) in α-gal metabolism. The ADGal enzyme cleaves terminal α-galactose moieties from glycoproteins and glycolipids, whereas β-1,4GalT transfers α-galactose to a β1,4 terminal linkage acceptor sugars: GlcNAc, Glc, and Xyl in various processes of glycoconjugate synthesis. An RNA interference approach was utilized to silence ADGal and β-1,4GalT in Am. americanum to examine their functional role in α-gal metabolism and AGS onset. Silencing of ADGal led to the significant down regulation of genes involved in galactose metabolism and transport in Am. americanum. Immunoblot and N-glycan analysis of the Am. americanum salivary glands showed a significant reduction in ⍰-gal levels in silenced tissues. However, there was no significant difference in the level of ⍰-gal in β-1,4GalT silenced tick salivary glands. A basophil-activation test showed a decrease in the frequency of activated basophil by ADGal silenced salivary glands. These results provide an insight into the role of α-D galactosidase & β-1,4GalT in tick biology and the probable involvement in the onset of AGS.


2021 ◽  
Vol 8 ◽  
Author(s):  
Irabonosi Obomighie ◽  
Kestutis Lapenas ◽  
Billy E. Murphy ◽  
Alexander M. C. Bowles ◽  
Ulrike Bechtold ◽  
...  

The p70 ribosomal S6 kinase (S6K) family is a group of highly conserved kinases in eukaryotes that regulates cell growth, cell proliferation, and stress response via modulating protein synthesis and ribosomal biogenesis. S6Ks are downstream effectors of the Target of Rapamycin (TOR) pathway, which connects nutrient and energy signaling to growth and homeostasis, under normal and stress conditions. The plant S6K family includes two isoforms, S6K1 and S6K2, which, despite their high level of sequence similarity, have distinct functions and regulation mechanisms. Significant advances on the characterization of human S6Ks have occurred in the past few years, while studies on plant S6Ks are scarce. In this article, we review expression and activation of the two S6K isoforms in plants and we discuss their roles in mediating responses to stresses and developmental cues.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Luisa Zanolli Moreno ◽  
Renata Paixão ◽  
Debora Dirani Sena de Gobbi ◽  
Daniele Cristine Raimundo ◽  
Thais Sebastiana Porfida Ferreira ◽  
...  

In the last decade, atypicalListeria monocytogenesandL. innocuastrains have been detected in food and the environment. Because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. In this study, we performed phenotypic and genotypic characterization of atypicalL. monocytogenesandL. innocuaisolates obtained from swine slaughterhouses and meat markets. Forty strains were studied, including isolates ofL. monocytogenesandL. innocuawith low-hemolytic activity. The isolates were characterized using conventional phenotypicListeriaidentification tests and by the detection and analysis ofL. monocytogenes-specific genes. Analysis of 16S rRNA was used for the molecular identification of theListeriaspecies. TheL. monocytogenesisolates were positive for all of the virulence genes studied. The atypicalL. innocuastrains were positive forhly, plcA,andinlC. Mutations in the InlC, InlB, InlA, PI-PLC, PC-PLC, and PrfA proteins were detected in the atypical isolates. Furtherin vitroand transcriptomic studies are being developed to confirm the role of these mutations inListeriavirulence.


2004 ◽  
Vol 54 (3) ◽  
pp. 961-968 ◽  
Author(s):  
Einat Zchori-Fein ◽  
Steve J. Perlman ◽  
Suzanne E. Kelly ◽  
Nurit Katzir ◽  
Martha S. Hunter

Previously, analysis of 16S rDNA sequences placed a newly discovered lineage of bacterial symbionts of arthropods in the ‘Bacteroidetes’. This symbiont lineage is associated with a number of diverse host reproductive manipulations, including induction of parthenogenesis in several Encarsia parasitoid wasps (Hymenoptera: Aphelinidae). In this study, electron microscopy and phylogenetic analysis of the 16S rRNA and gyrB genes of symbionts from Encarsia hispida and Encarsia pergandiella are used to describe and further characterize these bacteria. Phylogenetic analyses based on these two genes showed that the Encarsia symbionts are allied with the Cytophaga aurantiaca lineage within the ‘Bacteroidetes’, with their closest described relative being the acanthamoeba symbiont ‘Candidatus Amoebophilus asiaticus’. The Encarsia symbionts share 97 % 16S rDNA sequence similarity with Brevipalpus mite and Ixodes tick symbionts and 88 % sequence similarity with ‘Candidatus A. asiaticus’. Electron microscopy revealed that many of the bacteria found in the ovaries of the two Encarsia species contained a regular, brush-like array of microfilament-like structures that appear to be characteristic of the symbiont. Finally, the role of this bacterium in parthenogenesis induction in E. hispida was confirmed. Based on phylogenetic analyses and electron microscopy, classification of the symbionts from Encarsia as ‘Candidatus Cardinium hertigii’ is proposed.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
K Vomstein ◽  
S Reider ◽  
B Boettcher ◽  
K Feil ◽  
A Moschen ◽  
...  

Abstract Study question Uterine microbiota: are there differences within three major time points of the menstrual cycle in healthy controls, recurrent miscarriage (RM) and recurrent implantation failure (RIF) patients? Summary answer Compared to controls, RM and RIF patients showed an altered uterine microbiota throughout the menstrual cycle, with a lower dominance of lactobacilli. What is known already In contrast to the former notion of a sterile womb, bacterial colonization in the uterus and the placenta has been demonstrated. Studies showed that Lactobacillus-dominated endometrial microbiota correlate with reproductive success. Moreover, the presence of non-Lactobacillus-dominated microbiota, especially with detection of Gardnerella and Streptococcus in the endometrial fluid, seems to be associated with lower implantation-, ongoing pregnancy- and live birth-rates. However, intra-cycle variations in healthy women as well as possible alterations in patients with RM or RIF remain unknown. Study design, size, duration In total, n = 20 RM patients (≥ 3 consecutive miscarriages), n = 20 RIF patients (≥3 fresh or frozen embryo transfers with negative serum hCG, good quality embryos) and n = 10 healthy controls (no pregnancy) were included in this study. All patients had a 28 day menstrual cycle. During follicular, ovulatory and luteal-phase, after a thorough cleaning of the cervix, a flexible catheter was introduced into the uterine cavity and a uterine flushing with 1ml of NaCl was performed. Participants/materials, setting, methods Bacterial DNA was extracted using a QIAamp DNA kit (Qiagen) in combination with a PrecellysR24 homogenizer (Peqlab, Erlangen, Germany) according to the manufacturer’s instructions. The V3-V4 region of the bacterial 16S rRNA gene was amplified. Samples were pooled in equimolar ratios and progressed to pyrosequencing using an Illumina MiSeq se-quencer with MiSeq Kit V2 (250 bp paired-end). Analysis of 16S rRNA data, including alpha- and beta-diversity, were calculated using the phyloseq package in R. Main results and the role of chance For the Shannon index (species richness and evenness) a significant decrease during the ovulation period was shown in the control group, indicating a more uniform microbiota (p &lt; 0.05). This loss of diversity was not shown in RIF and RM patients. Overall, we could observe a higher similarity in taxonomic distribution in RM compared to the RIF patients. Longitudinal dynamics included increases in Firmicutes (CTRL and RM only) and a concomitant loss of Proteobacteria. Notably, significant amounts of bacteroides were only detected in the RIF patients. Actinobacteria were more frequent in both, RM and RIF as compared to controls. Limitations, reasons for caution To minimize the impact of a potential contamination, we performed pre-experiments with paired samples both from the vaginal fornix and the endometrial cavum and could show a significant difference in overall microbiome configuration. However, the route of sample can still be prone to contamination. Wider implications of the findings For the first time, we were able to show cycle-dependent alterations in the endometrial microbiome. These findings underline the role of an altered endometrial microbiome as a cause for RM and RIF and can contribute to the future establishment of therapeutic strategies in cases of a dysbalanced microbiome. Trial registration number Drks00020803


2019 ◽  
Author(s):  
Eleni Priglinger ◽  
Karin Strohmeier ◽  
Moritz Weigl ◽  
Carolin Lindner ◽  
Martin Barsch ◽  
...  

AbstractLipedema is a chronic, progressive disease of adipose tissue with lack of consistent diagnostic criteria. The aim of this study was a thorough comparative characterization of extracellular microRNAs from the stromal vascular fraction (SVF) of healthy and lipedema adipose tissue. For this, we analyzed 187 extracellular microRNAs in concentrated conditioned media (cCM) and specifically in small extracellular vesicles (sEVs) enriched thereof by size exclusion chromatography. No significant difference in median particle size and concentration was observed between sEV fractions in healthy and lipedema. We found the majority of miRNAs located predominantly in cCM compared to sEV enriched fraction. Surprisingly, hierarchical clustering of the most variant miRNAs showed that only sEV miRNA profiles – but not cCM miRNAs – were impacted by lipedema. Seven sEV miRNAs (miR–16-5p, miR-29a-3p, miR-24-3p, miR-454-p, miR–144-5p, miR-130a-3p, let-7c-5p) were differently regulated in lipedema and healthy, whereas only one cCM miRNA (miR-188-5p) was significantly downregulated in lipedema. Comparing SVF from healthy and lipedema patients, we identified sEVs as the lipedema relevant miRNA fraction. This study contributes to identify the potential role of SVF secreted miRNAs in lipedema.


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